The invention relates to an apparatus for manipulating a bobbin, in particular a flanged bobbin at a winding machine according to the precharacterizing clause of claim 1.
To wind threads, tapes, filaments or the like onto bobbins, winding machines are used that comprise a chuck onto which one or more bobbin tubes are set. The filamentary material is then wound onto the bobbin tube. As soon as the resulting package has reached a preset final diameter or a preset final weight, the package is taken off the chuck and stored or processed further. The process of taking away the completed package and replacing it with an unwound bobbin tube is called doffing.
For very large and heavy packages flanged bobbins are often used, with flanges so dimensioned that the package can be transported by resting it on the flanges and rolling it on the floor. To remove full packages from the chuck and also to set unwound bobbin tubes thereon, a freely movable doffing carriage is used, which grips the flanged bobbin, pulls it off (or pushes it onto) the chuck and sets it down on the floor (or raises it therefrom). The operation of this equipment is an elaborate procedure.
The object of the invention is to disclose an apparatus with which to manipulate a package or bobbin at a winding machine that simplifies the doffing procedure, i.e. the process of exchanging a package for an empty bobbin.
This object is achieved by an apparatus according to claim 1.
It is an important point of the invention that guide mechanisms are provided for the low-friction guidance of the doffing carriage with or without raised package, so that the doffing carriage need not be moved on the floor, which obviously is associated with various problems. That is, to achieve the stated object a doffing carriage is provided with lifting devices to raise and lower a package or bobbin between a winding height, at which the bobbin can be pushed onto or pulled off a chuck of the winding machine, and a transport height, at which the package can be rolled while resting on the floor or on a conveyor belt running in front of the winding machine, wherein a guide mechanism is further provided for the low-friction guidance of the doffing carriage with or without raised bobbin in a transport direction parallel to the chuck, between a winding position for winding the bobbins and a transport position in which the bobbins or packages are transported towards or away from the machine.
Preferably the guide mechanism is fixedly attached to the winding machine in the transport direction. As a result, between the doffing carriage and the winding machine no forces can arise that could be exerted on the winding machine relative to the site where it is installed.
Preferably the lifting devices are designed to support the flanged bobbin at its two flanges so that no bending forces or moments of tilt act on the flanges. In the case of bobbins without flanges, the package is supported directly by way of the wound material.
The guide mechanism is preferably so constructed that when the bobbin is in the winding position, the lifting devices are in the region of the flanges, so that they do not interfere with the winding process.
The lifting devices are preferably so constructed that when the package is in the transport position, they release it and can be shifted into the winding position. The package is thus free and can be rolled or otherwise transported away.
Preferably the guide mechanisms comprise straight guides or telescopic guides which are attached to the winding machine. With this arrangement it is particularly simply and effectively ensured that when a wound package is taken off or an empty bobbin tube is put on, no forces are exerted on the winding machine relative to the site where it is installed.
Preferably the lifting devices for the bobbin comprise a pair of levers pivotably mounted on the doffing carriage, which with first gripping ends engage the flanges or, in the case of flangeless bobbins, grasp the package at its circumference, and which by way of second actuating ends can be moved so as to raise and lower the package, preferably by means of a common lifting cylinder. The axle about which the lever pivots corresponds to the axis of rotation of the telescopic guides. The gripping ends are so constructed that they can absorb forces acting in the direction of the chuck, inasmuch as the bobbin rests by way of both flanges on the elongated (in the direction of the chuck) lever ends. Therefore no moments of tilt act on the gripping ends.
The doffing carriage is preferably so constructed that it can be pushed manually, which enables simple manipulation. Because the guide mechanisms are so constructed as to generate little friction, therefore, it is ensured that the machine as a whole is easy to operate.